Table 2.

Examples of tick saliva molecules with immunomodulatory functions.

Category	Molecule	Function
Inhibition of T-cell activity	Salp15	Interferes with T cell receptor (TCR) signaling, IL-2 production, activation of CD4+ T cells by dendritic cells (117, 128).
	Sialostatin L	Inhibits cathepsin L, reducing antigen presentation and T cell activation (143). Inhibits production of IL-9 in mast cells and maturation of dendritic cells
Complement Inhibition	Salp20	Inhibits the alternative complement pathway, protecting pathogens from complement attack (58).
	ISAC	Negative regulator of alternative complement activation (104).
	IRAC I and II	Negative regulator of alternative complement activation (105).
Anti-inflammatory function	Histamine-binding proteins (HBP)	Neutralize histamine to suppress local inflammation (144).
	Prostaglandin E2	Modulates inflammatory responses and promotes vasodilaton (92). Inhibits T cell activation.
	Sialostatin L2	Reduces pro-inflammatory cytokine production (e.g., TNF-α, IL-12) by targeting cathepsins (143). Inhibits NLRC4-mediated inflammasome activation.
Anti-coagulant	Ixolaris	Inhibits thrombin generation and blood coagulation, supporting efficient blood-feeding (145).
	Serpins	Serin protease inhibitors regulating angiogenesis, inflammation, and tissue remodeling (146).
Immune cell recruitment	Tick salivary lectin pathway inhibitor (TSLP)	Impairs neutrophil phagocytosis and chemotaxis (64).
	Apyrase	Hydrolyzes ATP and ADP, inhibiting neutrophil activation and platelet aggregation (147).
	Evasins	Bind and neutralize host chemokines, effectively suppressing immune cell recruitment (98).